[Plugin: Recent Posts Slider] Notice in Admin mode

Hello,
my version is WP 3.3.2 and RPS 0.6.3. In my Admin screen i can read:
Notice: Undefined index: rps_opt_hidden in E:\www\wp_pure\wordpress\wp-content\plugins\recent-posts-slider\recent-posts-slider-admin.php on line 2
Could you correct it ?
Best regards
S.